Rapid responses to a strong experimental selection for heat hardening in the invasive whitefly Bemisia tabaci MEAM 1.
Adaptation to new environments is an important issue for invasive species as colonization depends on evolvability in their new distribution range. Here, we considered the case of the whitefly Bemisia tabaci MEAM 1 (Gennadius) (Hemiptera: Aleyrodidae), a pest that has recently invaded Colombia and where thermal adaptation has been proposed to explain its colonizing ability. An experimental evolution study was conducted to assess the evolutionary potential of B. tabaci in relation to its upper thermal limits, to explain its rapid adaptation during post-invasion periods. Selection for hardening capacity was conducted in four whitefly populations. We measured thermal responses in relation to fitness components (survival, fecundity, and viability) for 5-7 generations under a strong selection regime. Heat hardening responded rapidly in both sexes. This was expressed as an increase in survival, but not in fecundity or viability. These results suggest that thermal responses for heat hardening are not correlated and evolve independently. Increased survival after few generations of selection points to high adaptive potential in this insect, which leads to rapid post-invasion adaptation. Our study can help to predict population responses to environmental change and explain the colonizing ability of this pest.